Electric clock



(No Model.) 2 Sheets-Sheet 1.

R. BAUMANN 8v T. H. WURMB. ELECTRIC CLOCK.

No. 585,249. j/f Patented @une 29, 1897. w

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(No Model.) 2 SheetsHShee-t 2. R. BAUMANN 8v T. H. WURMB.

ELECTRIC CLOCK.

No. 585,249. Patented June 29,1897.

UNITED STATES PATENT OEEicE.

ROBERT BAUh'lANN AND 'lllEODORE ll. VURMB, OF ST. l'iOUlS, MISSOURI.

ELECTRIC CLOCK.

SPECIFICATION forming part of Letters Patent No. 585,249, dated June 29, 1897.

Application filed May 18, 1896. Serial No. 591,932. (No model.)

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Be it known that we, ROBERT BAUMANN and THEoDonE H. WURMB, of the city of St. Louis, State of Missouri, have invented certain new and useful Improvements in Electric Clocks and System of Operating the Same, of which the following` is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part hereof.

Our invention relates to the construction of electric clocks and to the system of operating the same from a master-clock.

In large public buildings, schools, office buidings, railroad depots, dsc., it is a matter of considerable importance that there should be uniformity in the time indicated by the different clocks. The clocks heretofore in use have been found to be very unreliable and require much attention.

To equip a large building with high-priced regulators that will not vary half a minute in a month or so is a very expensive accommodation, and the mechanical sign-clocks which have heretofore been in use have been found to vary so much in time that they are absolutely unreliable.

Spring-actuated clocks wound periodically by an electric motor or by an electromagnet actuating a spring-lever armature require excessive battery-power in order to overcome the necessary tension of the spring which drives the train of gears and operates the clock. These considerations have led us to our present invention, the object of which is to provide an electric clock which shall be at the same time simple in construction, economical in the consumption of electric power, and adapted for in and out door service un` der all conditions, which shall indicate uniform and correct time, and which shall be free of the difficulties heretofore existing, some of which are named above.

Our invention consists primarily of an electrom agnet provided with a rocking armature, which armature has a side pull and which operates through its connections the hands of clocks of the class hereinafter described.

Our invention further consists of a masterclock provided with a circuit-closer capable of carrying a current of considerable strength,

and, further, of the system for connecting several clocks together and operating the same synchronously by the operation of the masterclock.

Our invention consists, further, of the details of construction hereinafter described and claimed.

In the drawings, Figure 1 is a top plan view of our improved electric clock. Fig. 2 is a vertical sectional view on the line 2 2 of Fig. 1. Fig. 3 is a side elevation of the mechanism shown in Fig. l with a part of the casing removed and part of the mechanism broken away. Fig. et is a diagrammatic view illusstrating our improved system of operating electric clocks. Fig. 5 is a detail perspective of a hell-crank lever of which we make use.. Fig. 6 is a side elevation of a spring-washer of which we make use. Fig. 7 is a view of a modified form of the bell-crank shown in Fig. 5, showing` how the pawls used on the ends of said bell-crank may be made adjustable.

Our clock may be placed in a casing consisting of the side walls 1 and 2, the back wall 3, the glass front e, and the dial-plate 5. The frame of the clock mechanism may be attached to the back wall of the casing by means of the brackets G and 7.

The clock-frame consists of the back plate S and the front plate 9, connected together by the posts 10, and the screws 11 pass through the ends of the brackets G and 7, then through the back plate S of the clock-frame, and then into the posts 10. The screws 12 pass through the front plate 9 and into the posts 10.

The coils 13 and le are placed one above the other in horizontal position with the rear end of their cores 15 and 1G against the back plate 8 of the clock-frame, and the bar 17 is placed on the back side of said plate S in a vertical position and in alinement with the rear ends of said cores 15 and 16, and screws 1S and l0 are inserted through said bar, then through said plate 8, and into the ends of said cores 15 and 1G, the bar 17 thus forming the yoke of the electromagnet.

The plate 8 should be of non-magnetic niaterial, or, if preferred, the bar 17 may bc omitted and the plate 8 may be so constructed as to form the yoke ot the electromagnet.

Mounted in a horizontal posit-ion in the center of magnetic force, or, in other words, halfway between the cores 15 and 1G and in aposition parallel therewith, 'is a shaft 20. The rear end of said shaft is journaled in the plate S and the front end passes out through the plate 9 and is journaled therein. Fixed upon the shaft 2O at some distance in front of the plate S is a collar 21, the position ot' which may be adjusted and regulated by the setscrew 22. Rotatably mounted upon said shaft 2O in front of said collar 21 and abutting against said collar is a brass or non-magnetic collar 23, which forms the hub of the S-shaped armature 2t, which armature is so constructed that the attraction of the cores 15 and 1G gives it a rotary motion upon the shaft 20. The front ends or free ends of the cores 15 and 1G project through the coils 13 and la far enough so that the ends of the armature 2t are attracted to the side of said cores instead of to the faces of the ends of the cores, as in the magnets heretofore in use.

Rotatably mounted upon the shaft 2O directly in front of the armature 2t is a toothed wheel 25. rlhe hub 2G of said toothed wheel projects f orwardl y and the extreme frontend 27 of said hub is reduced in size, and a springwasher 2S (shown in plan in Fig. G) is rotatably mounted upon said end 27 of said hub. The outer edges of the spring-washer 28 engage against the disk 29, which is rigidly fixed upon the shaft 2O in front of said wz sher. A collar 20 is adjustably iixed to the shaft 2O directly behind the hub of the wheel 25 to sustain the pressure of the spring-washer 2S.

Mounted upon the shaft 2O in front of the plate 9 'is the usual gearing for operating the hands of the clock, which gearing consists of the spur-pinion 30, fixed to the said shaft 20, the spur-gear 31, rotatably mounted upon the stub-shaft 32, which is fixed to said plate 9, and the spur-pinion 33,1ixed to the hub of said gear 31 and meshing into the gear $4-, which is rotatably mounted upon the shaft 2O and connected to the collar 35, which collar carries the hour-hand of the clock.

The armature 24C is constructed of suitable magnetic material and is S-shaped in front elevation. lilith reference to a line drawn vertically through the centers of the cores 15 and 1G the upper half of the armature 2li is on one side of said line, preferably the left side, and the lower half of said armature is on the opposite side of said line. The faces 3G of the ends of the armature which are to contact with the side faces of the ends of the cores are constructed to lit said cores when in contact therewith. The cores are preferably circular, and the faces 36 are in the 'form of semicircular recesses designed to lit halfway around said cores, as shown in Fig. 2.

The upper end of the armature 21 contacts with the opposite side of its core from the side of the core with which the lower end of said armature contacts, thus giving said armature a rocking motion upon the shaft 20. In this form of rocking armature both ends of the armatu rc are attracted simultaneously, as distinguished from the rocking armature shown in our concurrent application, Serial No. 501,993, in whicn the ends of the armatures are attracted alternately.'

Projecting from the hub ot' the armature 2land at right angles to a line drawn through the centerof the cores 15 and 1G is an arm 37, having the bevel-face SS upon the upper side of its free end. Upon the upper end of said armature 2l is a lug 3f), to which is fixed a stud 40, and a pawl al is journaled upon said stud, said pawl -ll being designed to engage with its free end the teeth upon the wheel 25, as required to rotate said wheel bythe rocking of said armature 2l.

A bell-crank lever lt2, a perspective of which is shown in Fig. 5, isjournaled upon the post 10 at the upper left-hand cornerof the clockframe and in such a position relative to the wheel 25 that the lugs l-S and 1l altern ately en gage the teeth of said wheel. A pin passes through the lower end ot' said lever 42 in a position parallel with the lug lt, said pin Ll5 being designed to ride upon the bevel-face 3S of the arm 37. A leaf-spring Lliti is attached to the post 10, upon which said bell-crank lever Lt2 operates and passes downwardly to a position against the outer face of the lower end of said bell-crank +i2, shown in Fig. 2. The tension of the spring L tt will normally hold the lug al in engagement with the teeth of the wheel 25 and prevent said wheel from rotating. A leaf-spring 1-7 is attached to the post 10 at the lower left-hand corner ot' the clock-frame and extends upwardly and engages the teeth of the wheel 25, said leatspring being designed to prevent said wheel from rotating' backwardly at all times.

A set-screw t8 is horizontally positioned through the post 1() at the lower right-hand corner of the clock-frame, and a piece of rubber Lt9 is mounted upon the point of said setscrew and designed to engage the rear side ot the lower end of the armature 2l and act as a cushion to regulate and limit the length of stroke of the armature.

A pawl-faced block 50, having the oblong aperture 51, through which operates the screw 52, as shown in Fig. 7, may be substituted at one or both ends of the bell-crank lever 1l-2 in place ot' the lugs t3 and at, and thus said lever may be made adjustable.

XVe prefer to make the wheel 25 with one hundred and twenty teeth, and the length of the stroke between the face of the armature and the core should be equal to about the space occupied by a tooth and a half upon the wheel 25. 'lhen by means of the pawl ll, carried by the armature 2st, engaging the teeth of the wheel 25 each vibration of the armature toward its core will advance the wheel 25 one tooth. As the armature 2t is attracted the free end of the arm 37 is raised, thus raising the pin Ll5, resting upon the pawl-face 38, and rocking the bell-crank 4t2 and causing the lug 43 to swing downwardly and engage the TOO IIO

closes the clock-circuit, or, in other words, connects the wires G9 and 70, and the breaking of the circuit controlled by the battery 74C by the action of the master-clock releases the armature 7 7, and said armature is pushed away from the cores by the action of the spring 83, and the spring Set, being so set that it does not follow the bar 7S as it retreats, thus breaks the clock-circuit. One or two cells of the battery are sufficient in place of the battery 7i to operate the electromagnet 76 by the operation of the master-clock, as heretofore described. Each of the clocks to be operated being provided with batteries sufficient to operate its mechanism and each of these batteries being connected together and connected to the springs 83 and Si, it is obvious that every half-minute as the inaster-clock opens and closes the circuit through the battery 7a the clock-circuit" will be opened and closed by the vibration of the armature 77, carrying the bar 78.

A tow r-clock such as is described in our concurrent application hereinbefore referred to may be attached to wires 87 and S8 or several tower-clocks may be attached to these wires. v

It will be obvious to those familiar with the art that our red ueing the number of the teeth upon the wheel 25 to sixty instead of one hundred and twenty or by using one end of the platinum point upon the seconds-hand of the master-clock instead of using both ends the clocks may be made to operate once a minute instead of every half-minute7 or that by doubling the number of teeth upon the wheel 25 or by making four platinum peints upon the seconds-hand of the master-clock instead of two the clocks may be operated four times a minute.

Ne claiml. A side-pull rocking armature mounted upon the shaft of the clock, the arm 37 projecting at right angles from the center of said armature, the bell-crank lever 42 pivotally mounted upon one of the posts of said clock, the pin Lt5 attached to one end of said bellcrank lever and engaging the bevel-face 3S upon the free end of said arm 37, the lug La in position parallel with said pin 5, the toothed wheel 25 mounted upon the shaft of said clock and in position to be engaged by said lug il, the lug -tl upon the opposite end of said bellcrank lever 4f.) from the lug -l-l and in position. to engage the teeth of said wheel 25, substantially as specified.

2. Aside-pull rocking armature mounted upon the shaft of the clock, the arm 37 project-ing at right angles from the center of said armature, the bell-crank lever pivotally mounted upon one of the posts of said clock, the pin 45 attached to one end of said bellcrank lever and engaging the bevel-face E8 upon the free end of said arm 37, the lug fl-l1 in position parallel with said pin -l-, the toothed wheel 25 mounted upon the shaft of said clock and in position to be engagedvby said lug al, the lug 4-3 upon the opposite end of said bellcrank lever -l-L) from the lug it and in position to engage the teeth of said wheel 25, and a set-screw 48 carrying the rubber cushion tti upon its point adjustalily positioned in one of the posts of said clock to limit and regulate the length of stroke of said armature, substantially as specilied.

A side-pull rocking armature mounted upon the shaft of the clock, the arm 37 projecting at right angles Vfrom the center of said armature, the bell-crank lever -l pivotally mounted upon one of the posts of said clock, the pin Ll5 attached to one end of said bollcrank lever and engaging the bevel-face 131 upon the free end of said arm 37, the lug 4A- in position parallel with said pin -l-, the toothed wheel 25 mounted upon the shaft of said clock and in position to be engaged by said lug lill, the lug lf3 upon the opposite end of said bellcrank lever 4:2 from the lug llf-l and in position to engage the teeth of said wheel 25, and a leaf-spring i7 having its Vfree end engaging the teeth of the wheel 25, and the leaf-spring G engaging said bell-crank lever t2, substantially as specified.

In testimony whereof we affix our signatures in presence of two witnesses.

ROBERT BAUMANN. THEODORE Il. XVV'RNB. \Vitnesses:

S. G. WnLLs, Mann GRIFFIN. 

